1st Gen R53 Cooper S Strange whistle on acceleration

That is something the 1st gen S does. It is the throttle body whistling at part throttle.

It is more noticaeable with a CAI.

 

I just installed an Alta CAI and I can confirm that there's a very high-pitched whistle at one or two throttle positions. I never noticed it before the CAI but now I do. It's not loud enough to hear with the radio on, so it doesn't really bother me that much...

 

Go back to the OEM intake or the JCW intake and you'll be fine. If you look up the part in the catalog, it's actually called an intake muffler - part of the design is to reduce noise from the engine.

 

Most folks just get used to it.......I did.

 

I have the JCW intake modified for better flow and mine whistle like crazy at WOT, I actually like it. The only comments I ever get are positive.

 

Guess I'm lucky my JCW intake does not whistle. For that I am grateful.

 

My JCW whistles. I have removed the flap and cut the intake hole. I'm living with it for the added performance.

 

Instead of the Alta intake, I would switch to the JCW intake. It is a good flowing intake.
I use the Mini Madness JCW filter instead of the expensive OEM paper filter.
The JCW intake has a flap that opens at about 4500 RPM so you do not hear the whistle.

In my case, I removed the flap in an effort to gain more power, which did not happen. With the flap removed I can hear the whistle in certain conditions. My whistle is not too bad.

 

Mine has the flapper. Guess that is why no whistles.

 

Is anybody else getting a whistle at WOT? Mine only whistles when the pedal is maybe 1/4th of the way down, so only if I'm feathering the throttle in traffic or something like that.

The only thing I get with my CAI at WOT is a nice WHOOSH and the SC whine

 

I only get the loud supercharger whine at WOT. I like that sound.
I only get the whistle at partial/light throttle. I usually notice it while cruising on the highway and I accelerate slightly. The whistle is a little annoying.

 

Actually, I get 2 distinct whistles at different conditions. It depends on the air flow speed/volume over the whistle point (which is likely the TB). The whistle(s) depend on the throttle position and the rpm.
A free flowing intake and exhaust will have a tendency to whistle more. A free flowing CAI specifically will additionally allow you to better hear the SC whine and any inadvertent whistle noise back through the intake path and filter.

 

I have a stock intake & you are welcome to it. PM if you are interested.

 

Well, that would certainly solve your problem. :cornut:

Jim

 

i have an 06 MCS with the Alta CAI and mine whistled until i installed the DT BPV and it stopped. it also adds 1psi boost and is supposed to eliminate the yo-yo factor in MINIs. the DT BPV does hurt fuel economy a bit. i enjoy it and and have completely forgotten that it used to whistle. install it and be done with the whistle!

 

Mine did the whistle at part throttle when I had the Dinan intake on it (as it would with any open intake). Drove me up the freakin wall. Switched to the JCW to mask the whistle and all is well. My JCW intake is stock except for an AMSoil nanofilter - has flap, etc. intact (otherwise I'd still hear the whistle).

This is a "feature"... because otherwise there's no reason MINI would have designed the JCW airbox with the RPM activated flap the way they did... it's designed to open at RPMs above where the undesirable whistle occurs. If the whistle weren't an issue, the JCW airbox would have been a lot like the Dinan airbox.